Bob, I suspect a fault in your antenna system that is OK at 100 watts, but does something "funny" (like perhaps arc over) when 500 (or 250) watts is applied.
Does the same thing happen into a dummy load? If so, then it is a KPA500 problem, but if OK on a dummy load, take a good look at your antenna system. 73, Don W3FPR On 9/29/2011 8:43 PM, Robert Redmon wrote: > I put my KPA500 on 80 meters for the first time this morning, and it > faults after several characters. SWR as shown on both the K3 and the > KPA500 is 1.3:1. I reduced drive to 11w (250w out), and it still does > it. The first few cw characters, swr looks fine, but if I pause a bit > and hit the key again, swr jumps above 5:1 and the amp shuts down with a > "refl hi" fault. If I run the K3 barefoot at 100w, the swr is steady at > 1.3:1 no matter what I do. Anybody know what is going on? > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
